Module tools.jackson.databind
Package tools.jackson.databind.ser.jdk

Class MapSerializer

java.lang.Object
tools.jackson.databind.ValueSerializer<T>
tools.jackson.databind.ser.std.StdSerializer<T>
tools.jackson.databind.ser.std.StdContainerSerializer<Map<?,?>>
tools.jackson.databind.ser.jdk.MapSerializer
All Implemented Interfaces:
JsonFormatVisitable
public class MapSerializer extends StdContainerSerializer<Map<?,?>>
Standard serializer implementation for serializing {link java.util.Map} types.

Note: about the only configurable setting currently is ability to filter out entries with specified names.

  • Field Details

    • UNSPECIFIED_TYPE

      protected static final JavaType UNSPECIFIED_TYPE

    • MARKER_FOR_EMPTY

      public static final Object MARKER_FOR_EMPTY

    • _valueTypeIsStatic

      protected final boolean _valueTypeIsStatic
      Whether static types should be used for serialization of values or not (if not, dynamic runtime type is used)

    • _keyType

      protected final JavaType _keyType
      Declared type of keys

    • _valueType

      protected final JavaType _valueType
      Declared type of contained values

    • _keySerializer

      protected ValueSerializer<Object> _keySerializer
      Key serializer to use, if it can be statically determined

    • _valueSerializer

      protected ValueSerializer<Object> _valueSerializer
      Value serializer to use, if it can be statically determined

    • _valueTypeSerializer

      protected final TypeSerializer _valueTypeSerializer
      Type identifier serializer used for values, if any.

    • _ignoredEntries

      protected final Set<String> _ignoredEntries
      Set of entries to omit during serialization, if any

    • _includedEntries

      protected final Set<String> _includedEntries
      Set of entries to include during serialization, if null, it is ignored, empty will include nothing.
      Since:
      2.12

    • _filterId

      protected final Object _filterId
      Id of the property filter to use, if any; null if none.

    • _suppressableValue

      protected final Object _suppressableValue
      Value that indicates suppression mechanism to use for values contained; either "filter" (of which equals() is called), or marker value of MARKER_FOR_EMPTY, or null to indicate no filtering for non-null values. Note that inclusion value for Map instance itself is handled by caller (POJO property that refers to the Map value).

    • _suppressNulls

      protected final boolean _suppressNulls
      Flag that indicates what to do with `null` values, distinct from handling of _suppressableValue

    • _inclusionChecker

      protected final IgnorePropertiesUtil.Checker _inclusionChecker
      Helper object used for name-based filtering
      Since:
      2.12

    • _sortKeys

      protected final boolean _sortKeys
      Flag set if output is forced to be sorted by keys (usually due to annotation).

  • Constructor Details

  • Method Details

    • _withValueTypeSerializer

      protected MapSerializer _withValueTypeSerializer(TypeSerializer vts)
      Description copied from class: StdContainerSerializer
      Method that needs to be implemented to allow construction of a new serializer object with given TypeSerializer, used when addition type information is to be embedded.
      Specified by:
      _withValueTypeSerializer in class StdContainerSerializer<Map<?,?>>

    • withResolved

      protected MapSerializer withResolved(BeanProperty property, ValueSerializer<?> keySerializer, ValueSerializer<?> valueSerializer, Set<String> ignored, Set<String> included, boolean sortKeys)

    • withFilterId

      public MapSerializer withFilterId(Object filterId)
      Description copied from class: ValueSerializer
      Mutant factory method that is called if contextual configuration indicates that a specific filter (as specified by filterId) is to be used for serialization.

      Default implementation simply returns this; sub-classes that do support filtering will need to create and return new instance if filter changes.

      Overrides:
      withFilterId in class ValueSerializer<Map<?,?>>

    • withContentInclusion

      public MapSerializer withContentInclusion(Object suppressableValue, boolean suppressNulls)
      Mutant factory for constructing an instance with different inclusion strategy for content (Map values).

      NOTE: only public because it is called by BasicSerializerFactory.

    • construct

      public static MapSerializer construct(JavaType mapType, boolean staticValueType, TypeSerializer vts, ValueSerializer<Object> keySerializer, ValueSerializer<Object> valueSerializer, Object filterId, Set<String> ignoredEntries, Set<String> includedEntries)

    • _ensureOverride

      protected void _ensureOverride(String method)

    • createContextual

      public ValueSerializer<?> createContextual(SerializationContext ctxt, BeanProperty property)
      Description copied from class: ValueSerializer
      Method called to see if a different (or differently configured) serializer is needed to serialize values of specified property (or, for root values, in which case `null` is passed). Note that instance that this method is called on is typically shared one and as a result method should NOT modify this instance but rather construct and return a new instance. This instance should only be returned as-is, in case it is already suitable for use.

      Note that method is only called once per POJO property, and for the first usage as root value serializer; it is not called for every serialization, as doing that would have significant performance impact; most serializers cache contextual instances for future use.

      Overrides:
      createContextual in class ValueSerializer<Map<?,?>>
      Parameters:
      ctxt - Context to use for accessing config, other serializers
      property - Property (defined by one or more accessors - field or method - used for accessing logical property value) for which serializer is used to be used; or, `null` for root value (or in cases where caller does not have this information, which is handled as root value case).
      Returns:
      Serializer to use for serializing values of specified property; may be this instance or a new instance.

    • getContentType

      public JavaType getContentType()
      Description copied from class: StdContainerSerializer
      Accessor for finding declared (static) element type for type this serializer is used for.
      Specified by:
      getContentType in class StdContainerSerializer<Map<?,?>>

    • getContentSerializer

      public ValueSerializer<?> getContentSerializer()
      Description copied from class: StdContainerSerializer
      Accessor for serializer used for serializing contents (List and array elements, Map values etc) of the container for which this serializer is used, if it is known statically. Note that for dynamic types this may return null; if so, caller has to instead use StdContainerSerializer.getContentType() and SerializationContext.findContentValueSerializer(tools.jackson.databind.JavaType, tools.jackson.databind.BeanProperty).
      Specified by:
      getContentSerializer in class StdContainerSerializer<Map<?,?>>

    • isEmpty

      public boolean isEmpty(SerializationContext prov, Map<?,?> value)
      Description copied from class: ValueSerializer
      Method called to check whether given serializable value is considered "empty" value (for purposes of suppressing serialization of empty values).

      Default implementation will consider only null values to be empty.

      Specified by:
      isEmpty in class StdContainerSerializer<Map<?,?>>

    • hasSingleElement

      public boolean hasSingleElement(Map<?,?> value)
      Description copied from class: StdContainerSerializer
      Method called to determine if the given value (of type handled by this serializer) contains exactly one element.

      Note: although it might seem sensible to instead define something like "getElementCount()" method, this would not work well for containers that do not keep track of size (like linked lists may not).

      Note, too, that this method is only called by serializer itself; and specifically is not used for non-array/collection types like Map or Map.Entry instances.

      Specified by:
      hasSingleElement in class StdContainerSerializer<Map<?,?>>

    • getKeySerializer

      public ValueSerializer<?> getKeySerializer()
      Accessor for currently assigned key serializer. Note that this may return null during construction of MapSerializer: depedencies are resolved during createContextual(tools.jackson.databind.SerializationContext, tools.jackson.databind.BeanProperty) method (which can be overridden by custom implementations), but for some dynamic types, it is possible that serializer is only resolved during actual serialization.

    • serialize

      public void serialize(Map<?,?> value, tools.jackson.core.JsonGenerator gen, SerializationContext provider) throws tools.jackson.core.JacksonException
      Description copied from class: ValueSerializer
      Method that can be called to ask implementation to serialize values of type this serializer handles.
      Specified by:
      serialize in class StdSerializer<Map<?,?>>
      Parameters:
      value - Value to serialize; can not be null.
      gen - Generator used to output resulting Json content
      provider - Context that can be used to get serializers for serializing Objects value contains, if any.
      Throws:
      tools.jackson.core.JacksonException

    • serializeWithType

      public void serializeWithType(Map<?,?> value, tools.jackson.core.JsonGenerator gen, SerializationContext ctxt, TypeSerializer typeSer) throws tools.jackson.core.JacksonException
      Description copied from class: ValueSerializer
      Method that can be called to ask implementation to serialize values of type this serializer handles, using specified type serializer for embedding necessary type information.

      Default implementation will throw UnsupportedOperationException to indicate that proper type handling needs to be implemented.

      For simple datatypes written as a single scalar value (JSON String, Number, Boolean), implementation would look like: 

        // note: method to call depends on whether this type is serialized as JSON scalar, object or Array!
  typeSer.writeTypePrefixForScalar(value, gen);
  serialize(value, gen, provider);
  typeSer.writeTypeSuffixForScalar(value, gen);
      and implementations for type serialized as JSON Arrays or Objects would differ slightly, as START-ARRAY/END-ARRAY and START-OBJECT/END-OBJECT pairs need to be properly handled with respect to serializing of contents.
      Overrides:
      serializeWithType in class ValueSerializer<Map<?,?>>
      Parameters:
      value - Value to serialize; can not be null.
      gen - Generator used to output resulting Json content
      ctxt - Context that can be used to get serializers for serializing Objects value contains, if any.
      typeSer - Type serializer to use for including type information
      Throws:
      tools.jackson.core.JacksonException

    • serializeWithoutTypeInfo

      public void serializeWithoutTypeInfo(Map<?,?> value, tools.jackson.core.JsonGenerator gen, SerializationContext ctxt) throws tools.jackson.core.JacksonException
      General-purpose serialization for contents without writing object type. Will suppress, filter and use custom serializers.

      NOTE: Public only since it also is called by AnyGetterWriter.

      Throws:
      tools.jackson.core.JacksonException

    • serializeEntries

      public void serializeEntries(Map<?,?> value, tools.jackson.core.JsonGenerator gen, SerializationContext provider) throws tools.jackson.core.JacksonException
      General-purpose serialization for contents, where we do not necessarily know the value serialization, but we do know that no value suppression is needed (which simplifies processing a bit)

      NOTE: public only because it is called by code from Guava TableSerializer

      Throws:
      tools.jackson.core.JacksonException

    • serializeOptionalFields

      public void serializeOptionalFields(Map<?,?> value, tools.jackson.core.JsonGenerator gen, SerializationContext provider, Object suppressableValue) throws tools.jackson.core.JacksonException
      Serialization method called when exclusion filtering needs to be applied.

      NOTE: public because other similar methods are (no current known external usage).

      Throws:
      tools.jackson.core.JacksonException

    • serializeEntriesUsing

      public void serializeEntriesUsing(Map<?,?> value, tools.jackson.core.JsonGenerator gen, SerializationContext provider, ValueSerializer<Object> ser) throws tools.jackson.core.JacksonException
      Method called to serialize fields, when the value type is statically known, so that value serializer is passed and does not need to be fetched from provider.

      NOTE: public because other similar methods are (no current known external usage).

      Throws:
      tools.jackson.core.JacksonException

    • serializeFilteredEntries

      public void serializeFilteredEntries(Map<?,?> value, tools.jackson.core.JsonGenerator gen, SerializationContext provider, PropertyFilter filter, Object suppressableValue) throws tools.jackson.core.JacksonException
      Helper method used when we have a JSON Filter to use for potentially filtering out Map entries.

      NOTE: public because other similar methods are (no current known external usage).

      Throws:
      tools.jackson.core.JacksonException

    • serializeTypedEntries

      public void serializeTypedEntries(Map<?,?> value, tools.jackson.core.JsonGenerator gen, SerializationContext provider, Object suppressableValue) throws tools.jackson.core.JacksonException

      NOTE: public because other similar methods are (no current known external usage).

      Throws:
      tools.jackson.core.JacksonException

    • serializeFilteredAnyProperties

      public void serializeFilteredAnyProperties(SerializationContext provider, tools.jackson.core.JsonGenerator gen, Object bean, Map<?,?> value, PropertyFilter filter, Object suppressableValue) throws tools.jackson.core.JacksonException
      Helper method used when we have a JSON Filter to use AND contents are "any properties" of a POJO.

      NOTE: public only because it is called by AnyGetterWriter

      Parameters:
      bean - Enclosing POJO that has any-getter used to obtain "any properties"
      Throws:
      tools.jackson.core.JacksonException

    • acceptJsonFormatVisitor

      public void acceptJsonFormatVisitor(JsonFormatVisitorWrapper visitor, JavaType typeHint)
      Description copied from class: StdSerializer
      Default implementation specifies no format. This behavior is usually overriden by custom serializers.
      Specified by:
      acceptJsonFormatVisitor in interface JsonFormatVisitable
      Overrides:
      acceptJsonFormatVisitor in class StdSerializer<Map<?,?>>
      typeHint - Type of element (entity like property) being visited

    • _orderEntries

      protected Map<?,?> _orderEntries(Map<?,?> input, tools.jackson.core.JsonGenerator gen, SerializationContext provider) throws tools.jackson.core.JacksonException
      Throws:
      tools.jackson.core.JacksonException

    • _hasNullKey

      protected boolean _hasNullKey(Map<?,?> input)

    • _writeNullKeyedEntry

      protected void _writeNullKeyedEntry(tools.jackson.core.JsonGenerator g, SerializationContext ctxt, Object value) throws tools.jackson.core.JacksonException
      Throws:
      tools.jackson.core.JacksonException